How Does It Work: Solar Energy

Finding a way to reduce our reliance on fossil fuels is one of the most important environmental challenge we face today, and what better way to green our electricity than with nature’s own energy source: the sun. The sun is a nearly inexhaustible source of power; in fact, there is more energy in the amount of sunlight that hits the earth in a hour than the whole planet uses in a year! So how can we capture that energy and put it to work for us?

How does solar energy work?

Use energy from the sun

Most of are familiar with one of the main technologies used to make solar power – the solar panel. You might have seen small-scale solar panels running local road signs or even giant solar farms in the desert collecting enough power for entire towns. These panels are composed of anywhere from a few dozen to hundreds of photovoltaic (PV; photo meaning light, voltaic meaning electricity) cells, which is what turns the sun’s energy into electricity. Inside a PV cell are layers of elements call conductors (usually silicon), which have electrons that can move around relatively easily. When sunlight strikes PV cells, the energy from the light excites the electrons, which are captured to create an electric current. Once electricity has been generated it can be used immediately or stored for later use (an important part of solar energy since, obviously, you can’t generate electricity when the sun’s not out).

A second type of solar energy is what’s known as concentrated solar power (CSP). CSP systems use mirrors or lenses to concentrate sunlight on a specific area, and the heat this creates is then used to create electricity, usually by making steam for traditional generators.

There are a number of advantages to solar energy. Once they’re up and running, solar panels produce zero emissions and require no additional fuel, and PV cells do not use any water (CSP systems do require water, however). And unlike fossil fuels, energy from the sun will never run out. Unfortunately, most solar panels on the market right now can only convert around 10% of the sunlight they receive into electricity, which means technology still has a way to go before we can rely on solar energy to meet our needs.

What can solar power be used for?

Solar Address Light

Once sunlight has been converted into electricity, that power can be used just like electricity from any other source. There are currently numerous large solar power stations worldwide supplying electricity in places like Germany, China, and Italy. Here in the U.S., solar power is concentrated, not surprisingly, in sunny areas like California, Arizona, Florida, and Nevada, but currently only about 1% of electricity generated in the U.S. comes from solar power.

As the technology improves, solar power is becoming more common in smaller applications as well. Single panels can be used to power road signs, parking meters, outdoor lighting, and other small devices, while office buildings can have solar panels installed on the roof to provide electricity for the whole building.

How can I make solar power work for me?

Solar Powered Laptop Portable Charger

If you live in an area with a solar power station, look into choosing an electricity supplier that uses solar energy (you can look on the Solar Energy Power Association’s website to find utilities in your area). If you’re more ambitious, it’s possible to have solar panels installed in your home so you can produce your own electricity. This route is still fairly expensive, but subsidies are available in a lot of areas as are programs where you pay in installments that cost no more than a normal electric bill. Manufacturers claim these solar panels will pay for themselves in 8 to 10 years.